package com.example.homework81;

import java.sql.*;

public class DBTest2 {
    String username;
    String password;
    public String RealName;

    public void getLoginInfo(String username, String password) {
        this.username = username;
        this.password = password;
    }


    public void userLogin() {
        String url = "jdbc:mysql://localhost:3306/library_management?allowPublicRetrieval=true&useSSL=false&serverTimezone=Asia/Shanghai";
        String DBusername = "root"; // 你的数据库用户名
        String DBpassword = "dwj061219!"; // 你的数据库密码

        Connection conn = null; // 声明一个Connection对象
        PreparedStatement prep = null;
        ResultSet resultSet = null;


        try {
            Class.forName ( "com.mysql.cj.jdbc.Driver" );
            conn = DriverManager.getConnection ( url , DBusername , DBpassword );
            System.out.println ( "数据库连接成功！连接对象: " + conn );

            // 你的数据库操作代码
            String sql = "SELECT * FROM user WHERE username = ? AND password = ?";
            prep = conn.prepareStatement ( sql );
            prep.setString ( 1 , username );
            prep.setString ( 2 , password );

            resultSet = prep.executeQuery ( );

            while (resultSet.next()) {
                RealName = resultSet.getString ( "name" );
                System.out.println("User ID: " + resultSet.getInt("id"));
                System.out.println("Username: " + resultSet.getString("username"));
                System.out.println("Password: " + resultSet.getString("password"));
                System.out.println("Email: " + resultSet.getString("email"));
            }


        } catch ( ClassNotFoundException e ) {
            e.printStackTrace ( );
        } catch ( SQLException e ) {
            e.printStackTrace ( );
        } finally {
            // 5. 关闭连接 (见下文)
            if ( conn != null ) {
                try {
                    conn.close ( );
                    System.out.println ( "数据库连接已关闭。" );
                } catch ( Exception e ) {
                    e.printStackTrace ( );
                }
            }
            if ( resultSet != null ) {
                try {
                    resultSet.close ( );
                } catch ( SQLException e ) {
                    e.printStackTrace ( );
                }
            }
            if ( prep != null ) {
                try {
                    prep.close ( );
                } catch ( SQLException e ) {
                    e.printStackTrace ( );
                }
            }
        }
    }
}